Dear Ed, Firatly, this is reply to ticket #104 (Clarify the interpretation of scalar coordinate variables), but I have moved to discussing scalar coordinates to the general list, as I don't think it will be constructive to clog up a third(!) trac ticket with this long running debate. We can always move back there, of course, as we see fit.
> Given that the spec is not clear I suspect the interpretation we are > debating may also be within user code rather than the libraries that > load the data from file. Despite this I support your call for > evidence so we can make an informed decision. I think the remit should be wide: Has anyone been actively using this interpretation, either in their own code or with third part libraries? I hope that we may find out. > I'm intrigued that you think units, bounds and/or a positive > attribute can combine to turn a scalar quantity into a vector > quantity. This goes to the heart of our disagreement. I see a CF-netCDF scalar coordinate as merely a shorthand for a a size 1, 1-d coordinate. This optional shorthand serves to remove the need to index data arrays along dimensions which have no variation (i.e. they have size 1). I very deliberately mentioned CF-netCDF since a CF-netCDF scalar coordinate is not a scalar in the abstract sense. This is because it explicitly applies to a dimension - albeit one which has been omitted from the file for human convienince. All the best, David -- David Hassell National Centre for Atmospheric Science (NCAS) Department of Meteorology, University of Reading, Earley Gate, PO Box 243, Reading RG6 6BB, U.K. Tel : +44 118 3785613 E-mail: d.c.hass...@reading.ac.uk _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata